mihaildev\elfinder\ElFinder::getSupportedLanguage PHP Method

    static function getSupportedLanguage($language)
    {
        $supportedLanguages = array('bg', 'jp', 'sk', 'cs', 'ko', 'th', 'de', 'lv', 'tr', 'el', 'nl', 'uk', 'es', 'no', 'vi', 'fr', 'pl', 'zh_CN', 'hr', 'pt_BR', 'zh_TW', 'hu', 'ro', 'it', 'ru', 'en');
        if (!in_array($language, $supportedLanguages)) {
            if (strpos($language, '-')) {
                $language = str_replace('-', '_', $language);
                if (!in_array($language, $supportedLanguages)) {
                    $language = substr($language, 0, strpos($language, '_'));
                    if (!in_array($language, $supportedLanguages)) {
                        $language = false;
                    }
                }
            } else {
                $language = false;
            }
        }
        return $language;
    }

 public function init()
 {
     parent::init();
     if (empty($this->language)) {
         $this->language = ElFinder::getSupportedLanguage(\Yii::$app->language);
     }
     if (empty($this->options['id'])) {
         $this->options['id'] = $this->getId();
     } else {
         $this->setId($this->options['id']);
     }
     $managerOptions = [];
     if (!empty($this->filter)) {
         $managerOptions['filter'] = $this->filter;
     }
     $managerOptions['callback'] = $this->getId() . "_manager";
     if (!empty($this->language)) {
         $managerOptions['lang'] = $this->language;
     }
     if (!empty($this->path)) {
         $managerOptions['path'] = $this->path;
     }
     $this->_managerOptions['url'] = ElFinder::getManagerUrl($this->controller, $managerOptions);
     $this->_managerOptions['width'] = $this->width;
     $this->_managerOptions['height'] = $this->height;
     $this->_managerOptions['id'] = $managerOptions['callback'];
 }